The proposed research is a revised application responding to program announcement PAR-06-039 entitled Dissemination and Implementation Research in Health. More than two decades of research have produced evidence-based approaches for preventing tobacco, alcohol, and other drugs during adolescence. New research is urgently needed to identify, develop, and refine effective and efficient methods, structures, and strategies that test models to disseminate and implement evidence-based prevention. The proposed research is designed to test the extent to which collaborative and adaptive systems-based approaches and structures will be effective at promoting the dissemination, adoption, implementation, and sustainability (DAIS) of evidence-based tobacco, alcohol, and drug abuse prevention. This study will assess the relative benefits of a systems-based adaptation-focused implementation effort versus a traditional (top- down) fidelity-focused one. The term system is used to refer both to the methodologies we will employ in developing DAIS efforts and to the organizational structures we will engage to support these efforts. Collaborative systems thinking methodologies will be used to design and manage DAIS efforts, and the system structure of the Cooperative Extension System (CES) will be used to support implementation. During Phase I (24 months), a systems methodology (concept mapping) will be utilized to enable the stakeholder community to identify key factors in the DAIS of evidence-based prevention in general, and facilitate the development of a systems approach to implementation of a specific evidence-based prevention program, Life Skills Training (LST). The systems approach will utilize concept mapping, adaptive systems thinking methods, and CES as the organizational support structure. Phases II (30 months) will consist of a randomized trial during which 50 middle schools including 4,000 participating students will be randomly assigned to one of the following conditions: (1) collaborative systems-based adaptive approach to implementation of LST and (2) standard fidelity-focused implementation of LST. The project will be conducted by an experienced team of scientists and staff from Cornell's Weill Medical College in New York City, Cornell's College of Human Ecology in Ithaca, and Cornell's Cooperative Extension Service located throughout New York State. The ultimate goal of the proposed research is to provide critical new knowledge to facilitate the widespread dissemination, adoption, implementation, and sustained utilization of evidence-based prevention in order to reduce tobacco, alcohol, and illicit drug abuse throughout the United States. PUBLIC HEALTH RELEVANCE: Considerable progress has been made in developing effective approaches to prevent tobacco, alcohol, and illicit drug use. However, these approaches have not been widely disseminated and utilized. The ultimate goal of the proposed research is to provide critical new knowledge to facilitate the widespread dissemination, adoption, implementation, and sustained utilization of evidence-based prevention in order to reduce tobacco, alcohol, and illicit drug abuse throughout the United States.